java swing：多边形填充颜色问题
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java swing : Polygon fill color problem
提问by lifeline2
Could any body diagnose the problem I am facing? As you run the demo you can see the middle part left blank, I need to fill the entire area..
任何机构都可以诊断出我面临的问题吗？当您运行演示时，您可以看到中间部分留空，我需要填充整个区域..
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class FillDemo
{
public static void main(String aths[])
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel pnl = new PolygonDemo();
pnl.setSize(100, 200);
f.getContentPane().add(pnl);
f.setSize(400,280);
f.setLocation(200,200);
f.setVisible(true);
}
}
class PolygonDemo extends JPanel
{
public PolygonDemo()
{
setBackground(Color.white);
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
Polygon p=new Polygon();
p.addPoint(100,0);
p.addPoint(100,100);
p.addPoint(0,100);
p.addPoint(0,0);
p.addPoint(80,0);
p.addPoint(80,20);
p.addPoint(40,20);
p.addPoint(40,40);
p.addPoint(80,40);
p.addPoint(80,100);
p.addPoint(20,100);
p.addPoint(20,80);
p.addPoint(60,80);
p.addPoint(60,60);
p.addPoint(20,60);
p.addPoint(20,0);
p.addPoint(0,0);
g2.setColor(Color.BLACK);
g2.draw(p);
g2.setColor(new Color(120,250,100));
g2.fillPolygon(p);
//g2.fillPolygon(p.xpoints,p.ypoints,p.npoints);
}
}
Many thanks in advance
提前谢谢了
回答by nokul
Your polygon intersects with itself. The fillPolygon method can not clearly decide which point is in and which is out. From the fillPolygon javadoc:
您的多边形与自身相交。fillPolygon 方法无法明确决定哪个点在里面，哪个点在外面。来自fillPolygon javadoc：
The area inside the polygon is defined using an even-odd fill rule, also known as the alternating rule.
多边形内的区域使用奇偶填充规则（也称为交替规则）定义。
Perhaps you can split your polygon into three single ones.
也许您可以将多边形分成三个单独的多边形。
回答by sathish
Draw Rectangle and Fill Color.....
绘制矩形并填充颜色.....
public void paint(Graphics g)
{
int[] xPoints = {100,50,150};
int[] yPoints = {100,200,200};
g.setColor(Color.black);
g.drawPolygon(xPoints, yPoints, 3);
g.setColor(Color.red);
g.fillPolygon(xPoints, yPoints, 3);
}
